<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<style>
			body{
				/* background-image: url(img/bg.jpg);
				 background-repeat: no-repeat; */
				 /* 背景随着页面滚动：scroll，默认值
				  页面滚动而背景固定：fixed*/
				 /* background-attachment: fixed; */
				/* background-position:20%; */
				background: gainsboro url(img/bg.jpg) no-repeat fixed center/100% 100%;
			}
			.box{
				width: 250px;
				height: 250px;
				border: 1px solid chartreuse;
				/* transparent:透明色 */
				background-color: aqua;
				
				/* 背景颜色重复显示：repeat
				 背景颜色不重复显示：no-repeat*/
				 background-repeat: no-repeat;
				font-size: 36px;
			}
		</style>
	</head>
	<body>
		<div class="box">
			这是盒子的内容
		</div>
	</body>
</html>
